Mold for casting rail crossings



July23, 1929. WBRMON 1,721,687.

MOLD FOR CASTING RAIL CBOSSINGS Filed April 23, 1925 2 Sheets-Sheet l 5 7 2 1 m" l w; 3

l I i 27 I July 23, 1929. w. BRINTON 1,721,637

MOLD FOR CASTING RAIL cnossmos Filed April 23, 1925 2 Sheets-Sheet 2 TIL Patented July 23, 1929.

UNITED STATES PATENT OFFICE.

WALTER BRINTON, OF WILMINGTON, DELAWARE, ASSIGNOR TO AMERICAN MANGA- NESE STEEL COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF MAINE.

MOLD FOR CASTING RAIL CROSSINGS.

Application filed April 23, 1925.

This invention relates to steel castings in form which renders them suitable to constitutc the intersecting portions of railway rails at track crossings, and particularly to crossing members employing in their form tread surfaces, flangeways, and guards, in one integral structure. It has heretofore been proposed to use, in the production of molds for these crossing members, chills which will have the effect of improving the texture of certain portions of the surface of the metal, for instance, chills in the form of round rods in positions to give form to the bottoms of the grooves or flangeways, but these chills, except for improvement of the immediate surface which they defined, did not substantially improve the casting as a whole, for the reason that they left relatively large masses of the casting constituting the sides of the flangeways as well as the surfaces of the tread and guard without material. structural change.

I have discovered by experiment and observation that a cause of failure which is encountered in a substan tial proportion of cast crossing members arises from the fact that the relatively thin supporting webs and. base flanges of the crossing member cool too quickly in comparison with the tread, flangeway, and guard portion which collectively involve a substantially greater mass, with the result that contraction incident to cooling of the last-named areas after the first-named port-ions have become set, results in undesirable drawing and attenuation of the metal.

Now, one object of the present invention is to devise a method of chill casting or molding railway crossing members which will have the effect of cooling not only the flangeways but the tread and guard portions, and, in fact, the whole of the greater mass area of the casting, sufliciently in advance of the cooling of the remainder of the casting to insure a free and unretarded flow of metal inward toward the greater mass, and thereby produce the desired density and texture of the metal in this mass and do'away with the inherent conditions which detract from the durability and resistance to cracking of the member when in service. To this end, one feature of the invention consists in producing the portion of the mold which defines the flangeways and their walls, the tread surfaces, and the upper surfaces of the guards, from a chill member which has the Serial No. 25 522 effect of causing rapid setting of such portions of the casting as well as areas adjacent thereto; the supporting webs which extend from such chill cast portions being slowly cooled by reason of the relatively large surrounding mass of sand, so that the metal can flow freely to the chilled portions; and the mold being provided with runners contiguous to the web portions which manifest themselves in the form of swells or enlargements in the ultimate casting, and being lieneath the risers have the effect of increasing flow *apacity past the relatively thin web portions and into the greater mass area of the tread, guard, and flangeway.

Another object of the invention is to pro vide a chill zine mold for use in practicing the method identified with the first-named object; and, to this end, another feature of the invention consists in constructing the chill with not only intersecting ribs conforl'ning in section and location to the flangeways to be formed, but with a plate which provides those confines of the mold which give form to the tread and guard surfaces, and which plate is integral with and con stitutes the carrier for the flangcway ribs; the plate being preferably extended well beyond the areas of the surfaces which it is to form, for instance, by having its intermediate portions stand in the relation of diagonals to the intersecting elements of the crossing, thereby increasing the heat dissipating area.

In the accompanying drawings Figure 1 is a perspective view of a cast metal crossing member of typical design, as seen from above.

Figure 2 is a view of the same in in vertcd position.

Figure 3 is a perspective view of the chill.

Figure 4 is a sectional view in a plane which would correspond to the line 4-4 of Figure 2, and showing the chill assembled therewith; and

Figure 5 is a detail view in a vertical plane involving the line 5 -5 of Figure 2, but showing the complete mold with the chill and casting in place.

Referring to Figures 1 and 2, 1 represents the tread portions, 2 the guard portions, 3

the fiangeways, 4, 5, the vertical webs, and 6 the base flanges of a railroad crossing member of known design, which is generally produced by the art of casting, and

which, for the sake of increased wearing qualities, is generally made of manganese steel. Owing to the reduced section of the parts 4:, 5 and 6. it frequently happens that these portions of the casting, as ordinarily molded, take on a setin advance of the portions 1, 2, and 3 of greater mass, with the result that as the portions 1, 2, and 3 cool, there is lacking the free fluidity of the metal which enables them to draw from the risers during contraction incident to cooling, in consequence of which the structure of the metal deteriorates, the parts wear more readily when in use, and cracking is liable to occur at the weakest point, namely, at the intersection of the flangeways 8. To remedy this dilliculty, the present invention forms that part of the mold which gives shape to the llangeways 3 and to the surfaces 1 and 2, out of a chill 7 (Figure 3) which comprises in its design flangeway ribs 8, tread-forming surfaces 9, and guardforming surfaces 10, and this chill constitutes the metal receiving surface at the bottom of the cavity in the drag section of the mold, as suggested in Figure 5. In addition to forming the faces 8, 9, and 10 described, the chill 7 involves in its form heat dissipating areas 11, 12, 13 and l t related as diagonals to the tread and guard surfaces described, and extending into the sand of the mold in a manner to increase heat distribution besides rendering the chill more secure against warping than if it were restricted. to the outline of the surfaces which it is to form.

As a further safeguard. a rainst deterioration in the structure of the metal in the greater mass area of the casting, flow-ways or runners l5, manifested in the finished casting by the lugs 15, are cored in the sand, within the channel of the crossing, and at vantage points therein. with respect to efiicient feeding of the metal, and these runners, being beneath the risers 16 and extending past the relatively thin web portions 4. of the casting and preferably intermediate of the ends of each arm of the cross, insure an ample supply of molten metal to feed the greater mass area during; cooling.

With a. mold constructed as described, the portions of the casting which are subjected to the greatest stresses in use will be insured as to density of metal. first, by causing such portions to be cooled in advance of other portions and while the other portions are still in a fluid state and therefore enabled to feed metal to supply contraction; and, secondly, by increasing the flow capacity toward the greater mass areas.

I claim:

1. A mold for casting railway crossings. having bases and treads integrally united by webs; said mold comprising; a base cavity, a tread cavity, a web cavity communicating with said base and tread cavities, and How cavities in addition to the web cavity communicating with the base and tread cavities and also with the web cavity, whereby metal is caused to flow simultaneously through the web cavity and said flow cavities in passing from one of the connected avities to the other.

2. A mold for casting railway crossings, having bases and treads integrally united by webs; said mold comprising a base cavity, a tread cavity, a web cavity communicating with said base and tread cavities, and ilow cavities in addition to the web cavity communicating with the base and tread cavities and also with the web cavity, whereby metal. is caused to flow simultaneously through the web cavity and said flow cavities in passing from one of the connected cavities to the other; the base cavity being provided with an intake opening for the molten metal; and the wall of the tread cavity which forms the wearing surface of the tread when in. use being provided by a chill.

A mold for casting railway crossings, having; bases and treads integrally united by webs; said mold comprising a base cavity, a tread cavity, a web cavity comn1unieating with said base and tread cavities, and flow cavities in addition to the web cavity communicating with the base and tread cavities and also with the web cavity, whereby metal is caused to flow simultaneously through the web cavity and said flow cavities in passing from one of the connected *avities to the other; the base cavity being provided with an intake opening for the molten metal; the wall of the tread cavity which forms the wearing surface of the tread when in use being provided by a chill; and said chill extending integrally beneath a. plurality of branching portions of the mold and having webs extending diagonally from one branching port-ion to another and thereby increasing heat transfer from the wearing surfaces of the cast.

Signed at New Castle,'Delaware, this 3rd day of April, 1925.

lVALTER BRIUTON. 

